A hijacked military helicopter has attacked Venezuela’s Supreme Court and a government ministry with gunfire and grenades. President Nicolas Maduro described the incident as a “terrorist attack.”

The helicopter was stolen from a military base in La Carlota by a group led by police pilot Oscar Perez. The vehicle flew over the Venezuelan capital, Caracas, and attacked government institutions on Tuesday. After firing 15 shots at the Interior Ministry from the helicopter, the hijackers flew to the Supreme Court building, where they dropped four grenades of Colombian and Israeli origin, according to Ernesto Villegas, the minister of state for the revolutionary transformation of greater Caracas.

“Sooner rather than later, we are going to capture the helicopter and those behind this armed terrorist attack against the institutions of the country,” President Maduro said, as cited by Reuters.

Maduro added that “the entire armed forces” had been activated to secure peace in the country, AFP reported.

There were around 80 people inside the ministry building and judges were holding a meeting in the Supreme Court building at the moment of the attack. No casualties have been reported.

“They could have caused dozens of deaths,” Maduro said.

Social media users uploaded various videos appearing to show the helicopter attack. Shooting and explosions are heard in the background, as the helicopter circles over the city.